Automatic or semiautomatic firearm

In the sector relating to firearms, pistols occupy a position of prime importance. Owing to their small size and lightness, they may be "personalised" in the sense that they can be carried on one's person. Considering that they were capable of producing only a single shot up until the middle of the nineteenth century, this meant that people carried more than one pistol on their person so that they had a greater firing capacity.

In the attempts to produce a firearm capable of more than one shot a milestone was the development of a pistol commonly known by the name of "revolver" which, being able to fire 5 to 8 shots, satisfied this requirement.

For many years, until the beginning of the last century, the revolver remained the most common type of pistol: however, its main negative features, namely the limited number of shots and the long and hard travel movement of the trigger, led arms manufacturers to seek new solutions.

During the period spanning the 19^th and 20^th century, therefore, semiautomatic and automatic pistols first appeared: in the case of the former, a shot is fired whenever the trigger is pressed, whereas in the case of the latter, once the trigger is pressed, the shots continue to be fired until the trigger is released.

Both these models are therefore characterized by the fact of being able to fire in succession a large number of shots and in that the positioning of a new bullet, after firing, is performed without the need for manual action.

Moreover, in these firearms, the travel movement of trigger is on the contrary reduced to a simple gentle and smooth click.

During normal operation, in automatic and semiautomatic pistols, manual action is required only at the start of operation, i.e. when the so-called "slide" is retracted so as to allow chambering of the first bullet to be shot. Retraction of the slide, in fact, ensures that the breech bolt of the pistol disengages the opening allowing the bullets to access the barrel, thereby enabling the first of said bullets to project and be pushed into the firing position by the said breech bolt when the latter, driven by a return spring, returns into its advanced reference position. The dimensions and rigidity of the abovementioned spring are determined by its main function consisting in containing the thrust resulting from recoil.

Following firing of the first shot, as a result of the recoil effect, the slide is again pushed backwards, the breech bolt frees the barrel access opening for the second shot and chambers the second bullet when the return spring bring its back into the forwards position.

However, semiautomatic and/or automatic pistols completely lose their characteristic feature, consisting in the reduction, to a minimum, of the dead time between one shot and the next, in the event of jamming (unsuccessful chambering of a bullet) or misfire (no firing as a result of a defective primer).

In these situations, in fact, in order to resume firing, it is required to move the slide again manually; this therefore means losing one's aim and the firing position, with the risk of the being exposed to enemy fire. On given occasions the risk is so high that one is even induced to prefer still a revolver to this type of firearm.

The object of the present invention is therefore that of eliminating the abovementioned drawbacks.

The invention, as it is characterized by the claims, achieves the object by means of an emergency device which, following jamming or misfiring of the weapon, causes automatically a movement of the breech bolt in such a way as to chamber a new bullet.

The main advantage obtained by means of the present invention consists essentially in the fact that, even in the case of defective operation of the pistol during the firing action, manual action is not required.

This results in a series of further advantages, such as the possibility of maintaining the firing position, without losing one's concentration and without having to aim the firearm again.

Moreover, the invention is also applicable to other automatic or semiautomatic weapons, such as rifles.

Further advantages and characteristic features of the invention will become more clear from the detailed description which follows, provided with reference to the accompanying drawings which show a non-limiting example of embodiment thereof, where:

• Figure 1 shows an overall schematic side view of a first embodiment of the invention, with the slide retracted and with some parts removed so that other parts may be seen more clearly;
• Figure 2 shows a view of the invention which is similar to the preceding view, but with the slide in the forwards position, with some parts removed so that other parts may be seen more clearly;
• Figure 3 shows a top plan view of the invention corresponding to the position shown in Figure 2;
• Figure 4 shows a series of cross-sectional views of the invention as indicated in Figure 3;
• Figure 5 shows respectively a side view and a side and front view of some details of the invention;
• Figure 6 shows a schematic side view of a second embodiment of the invention, with some parts removed so that other parts may be seen more clearly;
• Figure 7 shows a top view of the invention, corresponding to the embodiment according to Figure 6;
• Figure 8 shows a cross-sectional view of the invention along VIII-VIII as indicated in Figure 6;
• Figure 9 shows a front view and a side view of a detail of the invention;
• Figure 10 shows a side view and front view of an embodiment of the invention similar to that shown in Figures 6 to 9, with some parts removed so that other parts may be seen more clearly;
• Figure 11 shows a side view and a front view of an embodiment modified with respect to that of Figure 10, with some parts removed so that other parts may be seen more clearly.

As can be seen from the figures, the invention concerns an automatic or semiautomatic firearm comprising a slide (1) provided with at least one breech bolt (1a) and firing pin (1b), a return spring (2) constrained to the slide (1) and able to cause the breech bolt (1a) to move forwards again after each shot, and a trigger (3). Moreover, an emergency device (4) allows the breech bolt (1a) and the entire slide (1) to be moved so as to ensure continued firing even in the event of a misfire.

Although a pistol has been shown in the figures, the same device may also be used in rifles, provided that they are automatic or semiautomatic.

The emergency device (4) may be realised in various ways: in a first embodiment, shown in Figures 1 to 5, suitable for application to fixed-barrel weapons, it connects the trigger (3) to the breech bolt (1a) so that the breech bolt (1a) and the entire slide (1) may be moved by means of further pressure on the trigger (3).

In this case, the emergency device (4) comprises a system of levers (5) and interference means (6) which allow the system of levers (5) to interact with the breech bolt (1a) so as to transfer the action exerted on the trigger (3) to the breech bolt (1a), causing retraction thereof together with the entire slide (1). In particular, in the example shown in the figures, the system of levers (5) comprises three levers (5a, 5b, 5c) with a fixed pin connected in series to as to cause the breech bolt (1a) to cover the distance of about 35 millimetres, corresponding to the span of the opening for expulsion and introduction of the bullets and interacting with each other so as that pressing of the trigger (3) causes an anti-clockwise rotation of the pin of the last lever (5c). The means (6) for interference of the systems of levers (5) with the breech bolt (1a) comprise a pair of arms (6a) which are free to rotate with respect to the pin of the last lever (5c) and are each able to actuate a corresponding tongue (6b) which is integral with the breech bolt (1a), so as to push the tongues (6b) backwards, following prolonged pressure on the trigger (3).

A further arrangement, which is designed to be used only on pistols, comprises a damping device (7) which is able to limit the recoil effect of the weapon after firing. The damping device (7) comprises a piston (7a) which extends parallel to the barrel (8) of the pistol (10) and is integral with the slide (1); the piston (7a) is also free to slide inside a hollow cylinder (7b) communicating with the barrel (8) by means of a channel (7c) so as to cause part of the gases generated at the time of firing to flow into the hollow cylinder (7c) and limit the stroke of the piston (7a) - which cannot compress the gases beyond a certain limit - and therefore of the slide (1).

Finally, the pistol comprises a breech bolt pre-mechanism (9) which is able to delay the recoil thereof. It consists of a rigid end-piece (9a) which is constrained to the breech bolt (1a) by means of a deformable spring (9b) which has the function of absorbing the thrust of the recoil effect and then transmitting it to the breech bolt (1a) and therefore to the slide (1).

The operating principle of this firearm is identical to that of automatic and semiautomatic pistols or rifles in the case of correct functioning of the firing and resetting sequence.

On the other hand, in the event of jamming or misfire, prolonged pressure on the trigger (3) will cause a rotation of the levers (5s, 5b, 5c) until they actuate the pair of arms (6a) acting on the tongues (6b) of the breech bolt (1a). They will push the breech bolt (1a) backwards until a new bullet is able to project sufficiently for it be "chambered" by the breech bolt (1a) during its return movement, following which the normal firing sequence is resumed.

The effect of the damping device (7) is that, in pistols, the prolonged pressure on the trigger (3) does not have to overcome an excessive resistance of the return spring (2), justifying the use of a relatively soft spring (2). In fact, whereas in the pistols normally used, the recoil effect is contained by the rigidity of the return spring (2), in this pistol this is performed by the damping device (7).

The design thereof in terms of dimensions will obviously take into account the fact that, while the breech bolt pre-mechanism (9) delays the recoil effect, a certain amount of the gases produced at the time of firing will finish inside the cylinder (7b) inside which the piston (7a) slides and that the piston (7a) itself must instantaneously cover the access aperture of the channel (7c) so as to compress the said gases and prevent them from travelling back up the channel (7c).

In a second embodiment, which is shown in Figures 6 to 11, suitable for application to firearms with a movable barrel, the emergency device (4) allows a part of the firing gases to be used for retraction of the slide (1), making use of the action which the gases under pressure exert on a piston (14), drawing the slide (1) backwards, providing a corresponding catch (15) is removed by means of manual operation of a lever (16) located in the vicinity of the trigger (3).

In this case, the emergency device (4) comprises at least one hollow cylinder (17) which is similar to that used as a damping device in the embodiment already described, a piston (14) housed inside the cylinder (17) and suitable for drawing the slide (1) backwards owing to the action of the firing gases, means (11) for transferring the firing gases from the barrel (8) to the cylinder (17) inside which the piston (14) is located, and means (12) for controlling the movement of the piston (14). The stroke of the latter must be sufficient to ensure that the slide (1) retracts, overcoming the resistance of the spring (2) by an amount sufficient to allow expulsion of the cartridge, i.e. about 35 millimetres.

The cylinder (17) extends parallel to the barrel (8) and may be situated below or above the latter, as is respectively shown in Figures 6 to 9 and Figures 10 to 11. Under normal conditions of use, i.e. in the absence of jamming or misfiring, the piston (14) occupies the rear part of the cylinder (17), leaving free the front part which is intended to act as a reservoir for the firing gases. Already after the first shot, in fact, this zone is filled with gas under pressure, owing to the presence of the means (11) for transferring the firing gases from the barrel (8) to the cylinder (14).

In Figures 6 to 9, the cylinder (17) is located underneath the barrel (8): as can be noted, here the means (11) for transferring the firing gases from the barrel (8) to the cylinder (17) comprise a removable element (19), in which there is a duct (18) able to connect the barrel (8) and the cylinder (17) and a non-return valve (21) able to allow the gases to pass from the barrel (8) to the cylinder (17) and not in the opposite direction.

The removable element (19) also comprises a pressure stabilizer (22) which is able to keep at a constant level the pressure of the gases inside the cylinder (17) or, to be more precise, inside its front part, inside which the firing gases are contained. The pressure stabilizer (22) is provided with a regulating valve (24) and a breather vent (25).

The removable element (19) also comprises a sheath (13) containing the duct (18) so as to assist any movements of the barrel (8) at the time of firing.

In Figures 10 and 11 the cylinder is instead located above the barrel (8): in this case, the means (11) for transferring the firing gases from the barrel (8) to the cylinder (17) consist of a channel (23) which directly connects together the two environments, in addition to the non-return valve (21) of the type already seen.

In this embodiment it is possible to envisage the use also of two cylinders (17) with the corresponding pistons (14) which, however, in order to avoid an excessive height of the pistol (10), will be conveniently non-aligned, as shown in Figure 11.

The means (12) for controlling the movement of the piston (14) comprise a catch (15) - which can be seen in Figures 6 and 10 - able to keep the piston (14) immobile in the rest position, and a lever (16) which can be operated manually and is able to disengage the catch (15) so as to allow the movement of the piston (14) under the thrust of the compressed firing gases. This occurs following the occurrence of jamming or misfiring and, for the maximum advantage of the invention, the lever (16) must be positioned in the vicinity of the thumb of the hand which grips the pistol (10), so that it is easily accessible in order to ensure maximum rapidity of operation, but also clearly separate from the trigger (3).

The invention thus conceived may be subject to numerous modifications and variations, all falling within the scope of the inventive idea. Moreover, all the details may be replaced by technically equivalent elements.

In practice, modifications and/or improvements falling nevertheless within the scope of the following claims, are obviously possible.